System and method for adaptable testing of backplane interconnections and a test tool incorporating the same

ABSTRACT

The present invention provides a system for, and method of, adaptable testing of backplane interconnections. In one embodiment, the system includes a board detector configured to determine a relative arrangement of a plurality of hardware boards populating positions associated with the backplane interconnections. Additionally, the system also includes a test coordinator coupled to the board detector and configured to adaptively backplane test at least a pair of the plurality of hardware boards based on the relative arrangement.

TECHNICAL FIELD OF THE INVENTION

The present invention is directed, in general, to system hardwaretesting and debugging and, more specifically, to a system and method foradaptable testing of backplane interconnections and a test toolincorporating the system or the method.

BACKGROUND OF THE INVENTION

Testing of hardware wiring boards in a system has become increasinglymore difficult to accomplish wherein key prerequisites include anappropriate level of testing that is accomplished in a timely manner.This is due, mainly, to an increasing complexity of the wiring boardsbrought about by smaller and more complex board components. There aremanually created test solutions or the use of special fixturing to anIn-Circuit Tester for a specific slot configuration. The manuallycreated tests, often using an automatically controlled probe, arebecoming more difficult due to this more complex technology. In somecases, the probe is not physically small enough to appropriately contactthe interconnections between the smaller circuit components.Additionally, when a large number of circuit boards need to be tested,manual testing is often too time consuming. The special fixturingapproach may entail a physical modification of the boards to be tested,which could add non-functional failure modes.

These testing modes have brought about the use of components havingbuilt-in testing circuitry that allows more automated testing of thecircuit boards. These components are generally referred to as boundaryscan components, and the IEEE Standard 1149.1 governing design,registers, protocols and testing of boundary scan components isemployed. Some commercial boundary scan tool suppliers have developedmethods to adapt board level test generation to a backplane.Unfortunately, all these solutions assume there is a fixed or setconfiguration of boards in backplane slots that will not change. Thus,these solutions will not be able to adapt to the need where a system mayrequire multiple configurations in a given backplane depending on acustomer's order (e.g., telecommunications systems).

Accordingly, what is needed in the art is an enhanced way to providetesting support for all system configurations that may be provided in acommon backplane.

SUMMARY OF THE INVENTION

To address the above-discussed deficiencies of the prior art, thepresent invention provides a system for adaptable testing of backplaneinterconnections. In one embodiment, the system includes a boarddetector configured to determine a relative arrangement of a pluralityof hardware boards populating positions associated with the backplaneinterconnections. Additionally, the system also includes a testcoordinator coupled to the board detector and configured to adaptivelybackplane test at least a pair of the plurality of hardware boards basedon the relative arrangement.

In another aspect, the present invention provides a method for adaptabletesting of backplane interconnections. The method includes determining arelative arrangement of a plurality of hardware boards populatingpositions associated with the backplane interconnections and adaptivelybackplane testing at least a pair of the plurality of hardware boardsbased on the relative arrangement.

The present invention also provides, in yet another aspect, a test toolthat includes a test database, which provides a backplane positionstable and a backplane test data table and a system for adaptable testingof backplane interconnections. The system has a board detector thatdetermines a relative arrangement of a plurality of hardware boardspopulating positions associated with the backplane interconnections. Thesystem also has a test coordinator, coupled to the board detector, thatadaptively backplane tests at least a pair of the plurality of hardwareboards based on the relative arrangement.

The foregoing has outlined preferred and alternative features of thepresent invention so that those skilled in the art may better understandthe detailed description of the invention that follows. Additionalfeatures of the invention will be described hereinafter that form thesubject of the claims of the invention. Those skilled in the art shouldappreciate that they can readily use the disclosed conception andspecific embodiment as a basis for designing or modifying otherstructures for carrying out the same purposes of the present invention.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a block diagram of an embodiment of a test systemconstructed in accordance with the principles of the present invention;and

FIGS. 2A and 2B illustrate a flow diagram of an embodiment of a methodof adaptable testing of backplane interconnections carried out inaccordance with the principles of the present invention.

DETAILED DESCRIPTION

Referring initially to FIG. 1, illustrated is a block diagram of anembodiment of a test system, generally designated 100, constructed inaccordance with the principles of the present invention. The test system100 includes a test tool 105 for use with a backplane 120 and a failuredatabase 125. The illustrated exemplary system is intended to beextremely generic and is capable of performing tests on at least a pairof hardware boards coupled to the backplane 120. The test tool includesa test database 110 and a system for adaptable testing of backplaneinterconnections 115 (adaptable testing system 115) having a boarddetector 116 and a test coordinator 117. The backplane 120 includesboard slots having backplane interconnections 121 and first and secondhardware boards 122, 123 coupled to the backplane interconnections 121.

The illustrated embodiment of the present invention employs the IEEEstandard 1149.1 boundary scan technology. Additionally, test algorithmssuch as Walking 0, Walking 1, Up Count, Down Count, and Wagner or aproprietary test algorithm may be employed, as may be appropriate to aparticular application. Embodiments of the present inventionautomatically determine the arrangement or configuration of hardwareboards in the backplane 120 and apply the appropriate backplanepair-wise board tests needed to ensure proper operation. Additionally,these tests provide data necessary to diagnose a fault or failure.

The test tool 105 provides structural testing of backplaneinterconnections within a system using either existing or customizedcircuit boards. Testing goals include detecting any opens, shorts orstuck-at values and diagnosing which board, device, pin and net isassociated with the fault on the backplane or adjoining circuitry. Mostsystems will have an array of slots into which hardware boards ofvarious types may be inserted. The configuration of the system at thetime of the test will typically be unknown. At run-time, embodiments ofthe invention first determine how the system is configured and thenapply all the appropriate tests on pairs of boards, based on thisconfiguration. Additionally, associated software employed to apply thetests may be applied either externally, such as with a PC, or embeddedusing the existing resources of the system to be tested.

The test database provides a backplane positions table and a backplanetest data table corresponding to test board slots of the backplane 120and the backplane interconnections 121. An example of the backplanepositions table is shown in Table 1 below. TABLE 1 SLOT ID ADDRESS BOARDNAME TEST NAME 1 0x10 CHAN1 spchan 2 0x11 CHAN2 spchan 3 0x12 CHAN3spchan 4 0x13 CHAN4 spchan 5 0x20 CLCK1 spclck 6 0x21 CLCK2 spclckThe positions (or slots) table describes all testable slots associatedwith the backplane 120. Additionally, corresponding preliminary boardtests to determine if a particular board is a candidate to participatein a system level test are also included. The backplane positions ofTable 1 lists a slot identification number, address of the board in thatslot, board name and any test that is first performed on the hardwareboard before using it for backplane test purposes.

The backplane test data table describes what backplane tests may beapplied for any board pairs that are present in the system. An exampleof the backplane test data table is shown in Table 2 below. Thebackplane test data of Table 2 lists a test number, a test name, a nameof a first hardware board, an address of the first hardware board, aname of a second hardware board, an address of the second hardware boardand any predecessor test number associated with the test number. TABLE 2TEST TEST BOARD1 BOARD1 BOARD2 BOARD2 PREDECESSOR NUMBER NAME NAMEADDRESS NAME ADDRESS TEST NUMBER 1 CHAN1_CLCK1 CHAN1 0x10 CLCK1 0x20 0 2CHAN1_CLCK2 CHAN1 0x10 CLCK2 0x21 0 3 CHAN2_CLCK1 CHAN2 0x11 CLCK1 0x200 4 CHAN2_CLCK2 CHAN2 0x11 CLCK2 0x21 0 5 CHAN3_CLCK1 CHAN3 0x13 CLCK10x20 0 6 CHAN3_CLCK2 CHAN3 0x13 CLCK2 0x21 0 7 CHAN4_CLCK1 CHAN4 0x13CLCK1 0x20 0 8 CHAN4_CLCK2 CHAN4 0x13 CLCK2 0x21 0 9 CHAN1_CHAN2 CHAN10x10 CHAN2 0x11 0 10 CHAN2_CHAN3 CHAN2 0x11 CHAN3 0x12 0 11 CHAN3_CHAN4CHAN3 0x13 CHAN4 0x13 0 12 CHAN1_CHAN3 CHAN1 0x10 CHAN3 0x12 10 13CHAN2_CHAN4 CHAN2 0x11 CHAN4 0x13 11These tables are coded into a binary form together with all the teststhat can be applied and entered into a single test repository. This canthen be stored on either a local flash file system, downloaded andcopied into RAM memory or stored on an external server. The driving testsoftware may then read from this repository and apply the appropriatetests based on the automatically determined system configuration.

The board detector 116 determines a relative arrangement of a pluralityof hardware boards populating positions associated with the backplaneinterconnections 121 in the backplane 120. To determine the systemconfiguration of the hardware boards, each backplane slot is “pinged”using the supplied address to determine if it is populated with ahardware board, wherein this information is recorded for future use.Additionally, any test listed with the hardware board located in thisbackplane slot will be applied at this time, as referenced in Table 1.This test may be a test of the integrity of the boundary scan chain(path integrity test) on the board that is used for all subsequenttesting, as well as, any routine to disable the board from the system(disable test) to ensure that it is not driving on the backplane duringtests of other hardware boards. The board detector 116 therebydetermines whether each of the plurality of hardware boards is usablefor backplane testing.

The test coordinator 117 is coupled to the board detector 116 andadaptively backplane tests at least a pair of the plurality of hardwareboards based on the relative arrangement, represented in the illustratedembodiment by the first and second hardware boards 122, 123. After theboard detector 116 determines the system configuration, the testcoordinator 117 employs data from the backplane test data of Table 2 toiteratively execute the required backplane test based on theavailability of the hardware boards.

The backplane test data Table 2 includes a field at the end that listsany predecessor test. The purpose of this field is to eliminate anyredundant tests that may have already covered backplane nets in aprevious test. For example, in some systems a test may be used to testconnections between adjacent pairs of hardware boards in a system. Also,there may be a test that will test the same nets with a test betweenboards that are separated by one slot. The testing of one hardware boardto another hardware board where an empty slot exists between them onlyneeds to be applied if the pair wise tests between the adjacent slotsare not able to be performed due to an unpopulated slot. If all threeslots are populated, the populated/missing/populated test is redundantbecause the connections are tested with the adjacent hardware boardtests. The test coordinator 117 first determines if a predecessor testhas been executed before applying a backplane test employing the firstand second hardware boards 122, 123.

The failure database 125 serves as a repository for correlating faultconditions with hardware board and related backplane failures therebyallowing correlation between the two. The failure database 125 may be ageneric database covering a broad variety of testing situations that hasbeen acquired over extensive testing time. Alternatively, the failuredatabase 125 may be focused on a particular backplane and subsets ofapplicable hardware boards. Of course, the failure database 125 may be ahierarchal structuring of the two as appropriate to a particularapplication.

Turning now to FIGS. 2A and 2B, illustrated is a flow diagram of anembodiment of a method of adaptable testing of backplaneinterconnections, generally designated 200, carried out in accordancewith the principles of the present invention. FIG. 2A shows a portion ofthe method 200 that may be employed in determining a relativearrangement of a plurality of hardware boards populating positions orslots associated with the backplane interconnections. FIG. 2B shows aportion of the method 200 that may be employed in adaptively backplanetesting at least a pair of the plurality of hardware boards based on therelative arrangement.

The method 200 starts in a step 205. In a step 210, all test data isinitially read from external storage. Then, in a step 215, backplaneslots table data obtained in the step 210 is employed to iterate througheach of the backplane slots executing a board presence test for eachhardware board listed. A decisional step 220 determines if all of thebackplane slots have been tested. If there are remaining backplane slotsto be tested, a decisional step 225 determines if a hardware board ispresent in the backplane slot presently being addressed. If a hardwareboard is not present, the method 200 returns to the step 215 andproceeds to the next backplane slot. If the backplane slot contains ahardware board, a scan path integrity test and a disable test areexecuted on the hardware board, in a step 230.

Then, in a decisional step 235, it is determined if the tests weresuccessful. If a hardware board in a slot does not respond to a commonaddressing scheme based on the slot number, the slot is assumed to beunpopulated. If any of the scan path integrity test or disable testfails, backplane testing cannot proceed because the state of thebackplane signals from that slot is undefined. If the tests were notsuccessful in the decisional step 235, the method 200 again returns tothe step 215 wherein the next backplane slot is addressed, as before. Ifthe tests were successful, the hardware board is recorded as usable forbackplane testing in the step 240 and the method 200 returns to the step215 for further action. If the decisional step 220 determines that allbackplane slots have been addressed, the method 200 continues withbackplane testing as shown in FIG. 2B.

In the step 245, a test data table is employed to iterate through abackplane test list in testing a pair of the hardware boards. In adecisional step 250, it is determined if a pair of hardware boards beingaddressed are usable for backplane testing as was recorded in the step240. If either of the hardware boards is not usable for backplanetesting, the method 200 returns to the step 245. If both hardware boardsare usable for backplane testing, it is determined in a decisional step255 if there is a predecessor test that has already been executed. If apredecessor test has been executed, the method 200 returns to the step245 for further action.

If a predecessor test has not been executed, a backplane test isexecuted between specified hardware boards in a step 260. Then, a testresult is stored and displayed, and diagnostic data is employed toquantify a failure in a step 265. Then, a decisional step 270 determinesif all backplane tests have been performed. If all backplane tests havenot been performed, the method 200 again returns to the step 245 forfurther action. If all backplane tests have been performed, the method200 ends in a step 275.

While the method disclosed herein has been described and shown withreference to particular steps performed in a particular order, it willbe understood that these steps may be combined, subdivided, or reorderedto form an equivalent method without departing from the teachings of thepresent invention. Accordingly, unless specifically indicated herein,the order or the grouping of the steps is not a limitation of thepresent invention.

In summary, embodiments of the present invention employing a system forand a method of adaptable testing of backplane interconnections and atest tool employing the system or the method have been presented.Advantages include the ability, at run-time, to first determine how acollection of hardware boards are configured in a backplane arrangementand then apply all of the appropriate tests on at least pairs of boardsbased on the determined configuration. Additionally, data necessary todiagnose a failure identified by the testing may also be provided.Embodiments of the present invention typically allow application of allbackplane tests to be accomplished in a matter of seconds as may becontrasted to hours or even days using a manual method of testing.Additionally, comparisons between commercially available boundary scansolutions for a given hardware board configuration has been determinedto be about an order of magnitude slower than was achieved employingembodiments of the present invention for the same configuration.

Although the present invention has been described in detail, thoseskilled in the art should understand that they can make various changes,substitutions and alterations herein without departing from the spiritand scope of the invention in its broadest form.

1. A system for adaptable testing of backplane interconnections,comprising: a board detector configured to determine a relativearrangement of a plurality of hardware boards populating positionsassociated with said backplane interconnections; and a test coordinatorcoupled to said board detector and configured to adaptively backplanetest at least a pair of said plurality of hardware boards based on saidrelative arrangement.
 2. The system as recited in claim 1 furthercomprising a test database configured to provide a backplane positionstable and a backplane test data table.
 3. The system as recited in claim1 wherein said board detector is further configured to determine whethereach of said plurality of hardware boards is usable for backplanetesting.
 4. The system as recited in claim 3 wherein usability forbackplane testing is determined by an addressing test, a path integritytest and a disable test.
 5. The system as recited in claim 1 whereinsaid test coordinator is further configured to execute a predecessortest prior to backplane testing of said pair of said plurality ofhardware boards.
 6. The system as recited in claim 1 wherein backplanetesting provides data necessary to diagnose a fault condition associatedwith at least one of said backplane interconnections and said pluralityof hardware boards.
 7. The system as recited in claim 6 wherein saiddata necessary to diagnose said fault condition is coordinated with afailure database to isolate a cause of said fault condition.
 8. A methodfor adaptable testing of backplane interconnections, comprising:determining a relative arrangement of a plurality of hardware boardspopulating positions associated with said backplane interconnections;and adaptively backplane testing at least a pair of said plurality ofhardware boards based on said relative arrangement.
 9. The method asrecited in claim 8 further comprising a test database, said determiningemploying a backplane positions table and said adaptively backplanetesting employing a backplane test data table, retrieved from said testdatabase.
 10. The method as recited in claim 8 further comprisingdetermining whether each of said plurality of hardware boards is usablefor backplane testing.
 11. The method as recited in claim 10 whereinusability for backplane testing is determined by an addressing test, apath integrity test and a disable test.
 12. The method as recited inclaim 8 wherein said adaptively backplane testing is further configuredto execute a predecessor test prior to backplane testing of said pair ofsaid plurality of hardware boards.
 13. The method as recited in claim 8wherein backplane testing provides data necessary to diagnose a faultcondition associated with at least one of said backplaneinterconnections and said plurality of hardware boards.
 14. The methodas recited in claim 13 wherein said data necessary to diagnose saidfault condition is coordinated with a failure database to isolate acause of said fault condition.
 15. A test tool, comprising: a testdatabase that provides a backplane positions table and a backplane testdata table; a system for adaptable testing of backplaneinterconnections, including: a board detector that determines a relativearrangement of a plurality of hardware boards populating positionsassociated with said backplane interconnections, and a test coordinator,coupled to said board detector, that adaptively backplane tests at leasta pair of said plurality of hardware boards based on said relativearrangement.
 16. The test tool as recited in claim 15 wherein said boarddetector further determines whether each of said plurality of hardwareboards is usable for backplane testing.
 17. The test tool as recited inclaim 16 wherein usability for backplane testing is determined by anaddressing test, a path integrity test and a disable test.
 18. The testtool as recited in claim 15 wherein said test coordinator furtherexecutes a predecessor test prior to backplane testing of said pair ofsaid plurality of hardware boards.
 19. The test tool as recited in claim15 wherein backplane testing provides data necessary to diagnose a faultcondition associated with at least one of said backplaneinterconnections and said plurality of hardware boards.
 20. The testtool as recited in claim 19 wherein said data necessary to diagnose saidfault condition is coordinated with a failure database to isolate acause of said fault condition.